Slotted elements missing in AST

Describe the bug The AST for components using a slotted element is missing the slotted element.

Logs n/a

To Reproduce Compile <Component><div slot='foo'></div></Component> with Svelte 3.35.0 and look at the AST.

Expected behavior The AST should be as it was in 3.34.0 and include the <div>.

Stacktraces n/a

Information about your Svelte project: Svelte 3.35.0

Severity The right JS code looks like it’s still being generated, so this isn’t huge. But it will affect tooling. Medium-high I’d say.

Additional context This was brought to light by https://github.com/sveltejs/eslint-plugin-svelte3/issues/94

[dummdidumm]

I want to point out that language tools (with svelte2tsx), the prettier plugin and the eslint plugin all rely on the AST to some extend, so while the API is technically private, it’s still something we can’t change it at will.

[tanhauhau]

oh no 😦

I rearranged the children of the InlineComponent node to wrap <element slot="xxx">, <Component slot="xxx"> with <svelte:fragment slot="xxx">, and all the remaining elements with <svelte:fragment>

In this step, I mutated the AST node. (L114)

https://github.com/sveltejs/svelte/blob/1d6e20f2a967aebfa9c3eab769ca587345169632/src/compiler/compile/nodes/InlineComponent.ts#L109-L150

So, I have 2 options from here:

1. used the updated AST with <svelte:fragment> inserted

+ // assign back the children with updated children
+ info.children = children
  this.children = map_children(component, this, this.scope, children);

1. freeze the ast.html before mutation as well

https://github.com/sveltejs/svelte/blob/2925a00eff74414d5bc1d28a492e54ff827d00a6/src/compiler/compile/Component.ts#L117-L124

this.original_ast = {
	html: JSON.parse(JSON.stringify(ast.html)),
	css: ast.css,
	instance: ast.instance && JSON.parse(JSON.stringify(ast.instance)),
	module: ast.module
};

or rather

this.original_ast = JSON.parse(JSON.stringify({
	html: ast.html,
	css: ast.css,
	instance: ast.instance,
	module: ast.module
}));